Structure of cut-glass for wristwatch



March 17, 1970 MASAYOSHI AOKI 3,500,631

STRUCTURE OF CUT-GLASS FOR ,WRISTWATCH Filed March 22. 1968 4Sheets-Sheet 1 7/ F/ a. /A Q PRIOR ART 1 FIGJB PRIOR ART MASAYOSHI AOKISTRUCTURE OF CUT-GLASS FOR WRISTWATCH March 17, 1910 4 Sheets-Sheet 2Filed March 22. 1968 FIG. 2A

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PRIOR ART Man}! 17, 1970 MASAYOSHI AOKI I 3 STRUCTURE OF CUT-GLASS FORWRISTWATCH Filed March 22. 1968 4 Sheets-Sheet 3 F/G.3A 12mm;

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March 1970 MASAYOSHI AOKI. 3,500,

STRUCTURE OF CUT-GLASS FOR WRISTWATCH Filed March 22. 1968 4Sheets-Sheet 4 United States Patent 3,500,631 STRUCTURE OF CUT-GLASS FORWRISTWATCH Masayoshi Aoki, Tokyo, Japan, assignor to Kabushlki KaishaDaini Seikosha Filed Mar. 22, 1968, Ser. No. 715,340 Claims priority,application Japan, Mar. 24, 1967, 42/23,857 Int. Cl. G04b 39/00 US. CI.5891 3 Claims ABSTRACT OF THE DISCLOSURE A watch crystal assembly forcovering the faces of watches. The assembly includes an outertransparent member which is adapted to extend across and cover the faceof a watch and an inner ring which is adaptedto engage the bezel of thewatch and which has a surface visible through the outer member andformed with facets. As a result the thickness of the watch case need notbe increased to accommodate the watch crystal and the facets can beformed in a simple inexpensive manner.

BACKGROUND OF THE INVENTION The present invention relates to watches.

In particular, the present invention relates to watch crystals.

There are many different types of watch crystals known in the art. Ithas become customary in many watches to provide the watch crystal at theregion of its outer periphcry with a faceted surface which not onlyincreases the decorative effect but in addition distributes the lightaround the watch face in such a way as to improve the visibilitythereof. This invention relates particularly to this latter type ofconstruction.

At the present time many watches which have crystals of thisconstruction must have the thickness of the watch case increased inorder to accommodate the crystal. Because the crystal is provided in theregion of its outer periphery with the inner faceted surface, thecrystal extends undesirably inwardly beyond the bezel, and in order tomaintain the crystal at the required distance from the watch face it isnecessary to make the watch case thicker.

Attempts have been made to improve this latter construction, but eventhese latter attempts are not entirely satisfactory because with thebest known structures it is still necessary to form the facets on thewatch crystal, thus resulting in an exceedingly expensive structure.

SUMMARY OF THE INVENTION It is accordingly a primary object of thepresent invention to provide a watch crystal assembly which will avoidthe above drawbacks.

In particular, it is an object of the invention to provide a watchcrystal with a faceted peripheral region which can be manufactured atfar less cost than has hitherto been possible.

Also, it is an object of the invention to provide a watch crystal with afaceted peripheral region which although inexpensively manufactured canhave any desired combination of facets of any desired configuration toachieve whatever visual or decorative effects may be desired.

It is in addition an object of the present invention to provide a watchcrystal which does not necessitate a thickening of the watch case inorder to accommodate the crystal.

Thus, in accordance with the present invention the watch crystalassembly includes an outer transparent member which extends across andcovers the watch face. An inner ring of the watch crystal assembly isvisible 3,500,631 Patented Mar. 17, 1970 "ice through the outer memberthereof and has a faceted surface which is visible through the outermember. Because this inner ring is a separate component of the assemblyit is a simple matter to form the facets on the surface thereof which isvisible through the outer member of the crystal assembly.

BRIEF DESCRIPTION OF DRAWINGS The invention is illustrated by way ofexample in the accompanying drawings which form part of this applicationand in which:

FIG. 1A is a side view of a conventional watch crystal.

FIG. 1B is a top plan view of the crystal of FIG. 1A;

FIG. 10 shows the crystal of FIG. 1A in section mounted on aschematically illustrated Watch case;

FIG. 2A is a sectional elevation of another form of known crystal;

FIG. 2B is a top plan view of the crystal of FIG. 2A;

FIG. 2C is a schematic representation of the crystal of FIG. 2A mountedin a watch case;

FIG. 3A is a sectional elevation of a crystal assembly according to theinvention; 3AFIG. 3B is a top plan view of the structure of FIG.

FIG. 3C schematically illustrates how the structure of FIG. 3A ismounted on a watch case; and

FIGS. 4A-4G respectively illustrate the various possible differentconfigurations and combinations of facets which may be formed on thering of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to FIG. 1A, it willbe seen that the conventional cut-glass crystal 1 shown therein hasalong its inner peripheral surface an inclined, bevelled portion 1a, andthis portion is faceted in any desired manner so that when lookingdownwardly upon the structure of FIG. 1A, the watch crystal will havethe appearance indicated in FIG. 1B. This appearance is not onlydecorative but the brilliance of the illumination is also enhanced.

However, the structure of FIGS. 1A and 1B necessitates a bezel mountingas shown in FIG. 1C. Thus, referring to FIG. 10, it is to be noted thatthe bezel must be axially displaced from the watch face sufficiently toaccommodate the crystal 1 which extends inwardly beyond the exteriorgrooved inner periphery of the bezel of the watch case 2. For thisreason it becomes necessary to make the watch case 2 thicker than wouldotherwise be required. Moreover, the decorative and illumination effectswhich are achieved when the crystal of FIG. 1A is viewed by itself, asindicated in FIG. 1B, are not achieved in the assembly of FIG. 1Cbecause the presence of the bezel detracts from the effects which areotherwise achieved with the crystal by itself. The decorative and visualeffects which are achieved are interfered with and deteriorate becauseof the assembly of the structure with a bezel in the manner shown inFIG. 1C.

It has already been proposed to improve this latter construction ofFIGS. lA-lC by providing a structure as illustrated in FIGS. 2A2C. Thus,as may be seen from FIG. 2A, the watch crystal shown therein has notonly the outer face-covering portion 1, but also an outer peripheralflange 1b which is adapted to extend into engagement with the bezel.Surrounded by the flange 1b is an inner inclined or bevelled surface Inwhich is directly formed on the interior of the crystal 1 and which hasthe facets, as indicated in FIG. 1B. Thus, there is no question that thestructure of FIGS. 2A and 2B are superior to that of FIGS. 1A and 1B.The same visual and decorative effects are achieved. Moreover, when thecrystal of FIGS. 1A and 1B is mounted on the watch case 2 as shown inFIG. 2C, the crystal does not extend inwardly beyond the outerperipheral bezel groove which receives the flange 1b in the mannerindicated in FIG. 2C, so that the watch case 2 need not be thickened toaccommodate the crystal of FIGS. 2A and 2B.

In this latter connection, if FIGS. 1C and 2C are compared and it isassumed that the total thickness of the entire watch in both cases is T,then it will be seen that the dimension T of FIG. 1C, representing theextent to which the crystal extends beyond the watch case, is less thanthe dimension T of FIG. 2C which represents the same dimension. Itfollows, therefore, that the watch case thickness T of FIG. 1C isgreater than the watch case thickness T of FIG. 2C, and in fact it isquite clear that it is essential with the structure of FIGS. 1A and IEto provide a watch case 2 which has been suitably thickened toaccommodate the crystal.

It is furthermore to be noted that although the bezel of FIG. 1Cdetracts from the visual and decorative effects which can be achievedwith the crystal, this latter disadvantage also is eliminated with theconstruction of FIGS. 2A and 2B, since the bezel has no effect on thefaceted surface 1a. Even though the entire crystal structure of FIGS. 2Aand 2B is relatively thick, the decorative and visual effects do notdiminish because of the clear transparency of the glass.

However, the construction of FIGS. 2A2C do not provide a satisfactorysolution inasmuch as the design and workability of the glass availablefor the crystals of FIGS. 2A2C necessitate limitations. Because thefacets are situated directly on the glass surface in the interiorthereof in the manner indicated in FIG. 2A, the working of the glass canbe carried out only with great difficulty and the nature of the facetsis limited.

These drawbacks are avoided with the present invention which isillustrated in FIGS. 3A-3C.

Thus, referring to FIG. 3A, the watch crystal assembly of the inventionillustrated therein includes an outer member 1 which is adapted toextend across and cover the face of the watch and which is made of aclear transparent material such as any suitable glass. However, thefacets are not cut directly on the member 1 of FIG. 3A. Instead, thewatch crystal assembly of the invention is provided with a separateinner ring 3 which has a faceted surface 3a visible through the outermember 1. The ring 3.is made of the same material as the member 1. Thismember 1 has at its outer periphery an inwardly extending flangesurrounding the axis of the watch face and directly engaging the bezelin the manner shown in FIG. 3C. The separate ring 3 which is surroundedby and engages the exterior flange of the outer member 1 terminates inan inner face which is flush with the inner end face of the flange ofthe member 1 and which also engages the bezel in the manner shown inFIG. 3C. The faceted surface 3a on the other hand has an innerperipheral edge which is nearer to the watch face than the outerperipheral edge, this surface forming part of a cone whose apex is onthe same side of the member 1 as the ring 3. Therefore, with thisconstruction all of the advantages of the construction of FIGS. 2A and2B are achieved at far less cost because it becomes possible to providethe facets on the surface 3A before the ring 3 is assembled with themember 1. At this time the surface 311 is readily accessible so thatthere are no difficulties in forming the facets and there are nolimitations on the many different types of facets which can be provided.FIGS. 4A-4G illustrate various different possibilities, among many more,of the types and combinations of facets which can be very inexpensivelyprovided with the watch crystal assembly of the invention.

Therefore, even though the crystal of the invention is formed of theseparate components 1 and 3 which must be assembled together,nevertheless it is ossible to achieve the visual and decorative effectsindicated in FIG. 3B and the assembly of the invention can be mounted onthe watch case 2 without requiring the thickness of the latter to beincreased inasmuch as the inner end surface of the outer peripheralflange of member 1 directly engages the bezel and is situated in thesame plane as the inner end surface of the ring 3 which also directlyengages the bezel.

It is to be noted that the rings 3 are not only manufactured separatelyfrom the members 1, but in addition a large collection of such rings notonly of different faceted arrangements but also of different colors canbe kept on hand to be assembled with the member 1 of the crystalassembly according to the tastes and requirements of a given purchaser.

What is claimed is:

1. A *watch crystal assembly for mounting on the bezel of a watch casecomprising an outer member adapted to extend across and cover the faceof a watch and formed with an inwardly extending, bezel-engaging flangealong its outer periphery, and an inner bezel-engaging ring peripherallyengaging said outer member flange and having a faceted, lightdistributing, upper surface visible through said outer member, saidinner ring and outer member both being made of the same transparentmaterial.

2. The combination of claim 1 and wherein said ring and flange bothterminate in inner end faces which are in a common plane parallel to theplane defined by an inner bezel surface with which they engage.

3. The combination of claim 1 and wherein said faceted surface of saidring is situated at a face thereof which extends between an outerperiphery of the ring and an inner periphery thereof, said facetedsurface forming substantially part of a cone whose apex is situated inthe same side of said outer member as said ring.

References Cited FOREIGN PATENTS 1,384,590 11/1964 France.

934,018 8/ 1963 Great Britain. 301,498 9/ 1954 Switzerland.

STEPHEN J. TOMSKY, Primary Examiner G. H. MILLER, 1a., AssistantExaminer U1 C KR. 4

